Fume Hoods
Safety is the primary function of fume hoods. Proper performance and use of the fume hood are essential in providing safety to the user and other laboratory personnel. They exhaust toxic, flammable, noxious, or hazardous fumes and vapors by capturing, diluting, and exhausting these materials through the ductwork. If used correctly, fume hoods also provide spill containment and physical protection against fire and explosion.
How Fume Hoods Work
A fume hood is a ventilated enclosure in which gases, vapors, and fumes are contained. An exhaust fan on the top of the laboratory building pulls air (and airborne contaminants) through connected ductwork and exhausts them to the atmosphere.
UT Dallas has two types of fume hoods on campus:
- Constant volume (CV): where the quantity of air pulled through the hood is constant. When the sash is lowered, the velocity of airflow through the hood increases proportionally; thus, higher face velocities can be obtained by lowering the sash. Because the exhaust fan must run at a constant rate, this type of fume hood can be wasteful of energy when the fume hood is not in use.
- Variable air volume (VAV): where the quantity of air pulled through the hood varies as the sash is adjusted to maintain a set face velocity. Therefore, when the sash is lowered, the velocity of airflow through the hood stays the same. This type of fume hood is preferred for energy savings.
When to Use a Fume Hood
Fume hood use should be based on a risk assessment of the intended procedure. This assessment should consider characteristics of the materials used, experimental procedure, and skill and expertise of the user(s).
When should I contact Risk & Safety about my fume hood?
If any (or all) of the following is noticed, please contact the Office of Institutional Risk & Safety at safety@utdallas.edu, 972-883-7200, or through an incident report form.
- If the Kim-wipe test fails
- If the light in the fume hood is not working
- If you do not hear the fume hood motor running
- If you smell fumes or vapors when working in the hood
- If the hood has been relocated
- If you have a new hood in your lab
- If the current inspection sticker is missing, but the hood is not tagged out of service
How do I know my fume hood has passed certification?
Fume hoods that pass annual certification will have information on a sticker located on the frame of the hood. A valid certification sticker should have the date of inspection (within the last year), identifying information for the inspector, and the average face velocity. An example of a fume hood sticker is displayed below. If you notice that the certification sticker is missing or torn, but the fume hood is not tagged out of service, please email safety@utdallas.edu.
How do I know if my fume hood failed certification?
Fume hoods that fail certification are tagged out of service. A sign similar to the one displayed below is posted on the sash of failed hoods. Please DO NOT remove this sign OR use the fume hood tagged out of service until repairs are complete and the hood is recertified. It is the responsibility of the PI and laboratory personnel to ensure the fume hood is working properly. If you notice that a fume hood is not working, contact the Office of Institutional Risk and Safety.
Fume Hoods vs. Biosafety Cabinets
Occasionally, both fume hoods and biosafety cabinets are referred to as “hoods” and can be found next to each other in the same laboratory. This can be misleading, as these two pieces of equipment serve different purposes. Make sure you are using the proper containment equipment for your work.
| Chemical Fume Hood | Biological Safety Cabinet |
| Used for hazardous chemicals | Used for infectious biological agents |
| Protects the user | Protects the user, environment, and material |
| No HEPA filter | Exhaust is HEPA filtered |
| Exhausts air outside the building | Exhausts air back into the room (usually) |